On this verse compare 9.2 and 22.5. It was for this purpose may be understood in the sense the Good News Translation has taken the word (see Moffatt “on this business”), or in a temporal sense (see An American Translation* “once” and New English Bible “on one such occasion”), or in the sense of “under these circumstances.” Note, however, that the phrase for this purpose is important in relating the following paragraph to what has just preceded, namely, Paul’s intent to persecute the churches.

In Greek the word orders is singular and is rendered “commission” by many translators. The reference would be to a document indicating the authority given him by the High Priest. In some languages it is not possible to say I went to Damascus with the authority and orders. Since such authority and orders would be given in written form, one can only go with this type of document—for example, “I went to Damascus with a document which stated I had authority and orders from the chief priests.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .